The five-year grant will fund studies to better understand the biological and behavioral processes that lead to physical disability in older adults and help them prevent it.

Already researchers at the institute have found that higher levels of physical activity are associated with greater longevity, better mood and improved strength among older adults, said Dr. Marco Pahor, principal investigator and director of the UF Institute on Aging.

The research is particularly relevant to the Sunshine State, home to the largest and fastest-growing senior population in the country.

In Florida, 4.5 million residents are 60 or older, which puts the state first in the nation for the percentage of citizens who are seniors — about 24 percent, said Ashley Marshall, spokeswoman for the Florida Department of Elder Affairs.

By 2020, that number is expected to double to 9.7 million, she said. Within that population, the 85-to-100 age group is the fastest-growing, said Marshall, noting that the Older Americans Act uses age 60 or over to define “senior.”

Keeping that population strong and sound is in everyone’s best interest, experts say, because seniors will consume an ever-increasing portion of health-care spending.

“For the first time in our 20-year history, the number of seniors on our wait list for health-care services exceeds that which we can serve,” Marshall said. “That need will only increase unless something changes.”

That something may be finding ways to keep seniors more active, said Pahor, who also chairs the department of aging for the UF College of Medicine.

Muscle mass declines with age no matter what, Pahor said. As older adults lose strength, they lose the ability to do daily tasks.

Diabetes, stroke, heart disease and sedentary lifestyles also contribute to muscle loss, Pahor said. The answer, however, is not as simple as getting the elderly to exercise.

“Of course exercise helps, but it also puts seniors more at risk of falls and injuries, and even cardiovascular events,” he said. “The key is to find out what exercises are best, and the optimal amount and intensity.”